import sys
readline=sys.stdin.readline

N=int(readline())
inf=1<<30
ans=inf
X=list(map(int,readline().split()))
for i in range(N):
    for j in range(N):
        if X[i]!=X[j]:
            ans=min(ans,abs(X[i]-X[j]))
if ans==inf:
    ans=0
print(ans)